There is increasing evidence that those who experience changes in their life routine have a tendency to become physically ill. A large literature has reported attempts to achieve ratio measurement of life changes by the use of psychophysical measuring techniques. Other research using the resulting measures has shown that those scoring high in "life change units" are likely to become physically ill. The research in this are could be extended on several crucial fronts in the next two years through the exploratory research effort we are proposing. It is vital, we maintain, to study the cultural variation in the perceptions of the stressfulness of life changes and illness, particularly psychological impairment. Further, the cultural effects upon the linkages between life changes and illness need to be explored. In particular, we propose to investigate the differences between and among ethnically homogeneous groups in the perception of the relative degree of stress associated with various life changes and in the effect of stress upon illness. The ethnic groups to be studied include Anglos (in the strict sense of the word), Mexican Americans (2nd generation or more), 1st generation Mexican immigrants and Mexican nationals still residing in Mexico. The ethnically heterogeneous metropolitan area of El Paso-Ciudad Juarez is ideal for this type of research. The information discovered during the course of this research would, on the scholarly level, constitute a contribution to the developing literature on the etiology of psychological impairment. On a more applied level, the information discovered during the course of this research would be invaluable to medical health and mental workers in areas of ethnic heterogeneity. Professionals in health care delivery systems that service members of these groups could as a result of the study, develop insight into potential cultural differences and their relevance for health care and research problems.